Build acceleration: ccache, unity build, precompiled headers

- Auto-detect and use ccache as compiler launcher when available
- Add ENABLE_UNITY_BUILD option for jumbo builds (batch size 8)
- Precompile heavy STL/Boost/OpenSSL headers for C++ targets
- Exclude hash9 crypto from unity builds (colliding static symbols)
- Fix RAND_screen() compile error on OpenSSL 3.x (removed API)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CMakeLists.txt

@@ -6,7 +6,7 @@ if(POLICY CMP0167)
 endif()
 
 project(Triangles
-    VERSION 5.8.3
+    VERSION 5.9.0
     DESCRIPTION "Cryptographic Triangles Wallet"
     LANGUAGES C CXX
 )
@@ -17,6 +17,24 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 set(CMAKE_C_STANDARD 11)
 
+# ── Build acceleration ──
+# ccache: auto-detect and use if available
+find_program(CCACHE_PROGRAM ccache)
+if(CCACHE_PROGRAM)
+    set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    message(STATUS "ccache found: ${CCACHE_PROGRAM}")
+else()
+    message(STATUS "ccache not found — install it for faster rebuilds")
+endif()
+
+# Unity (jumbo) build: batch source files to reduce header parsing overhead
+option(ENABLE_UNITY_BUILD "Enable CMake unity (jumbo) builds" OFF)
+if(ENABLE_UNITY_BUILD)
+    set(CMAKE_UNITY_BUILD ON)
+    set(CMAKE_UNITY_BUILD_BATCH_SIZE 8)
+endif()
+
 # ── Output directories ──
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
@@ -113,4 +131,7 @@ message(STATUS "  D-Bus:              ${USE_DBUS}")
 message(STATUS "  ZMQ:                ${USE_ZMQ}")
 message(STATUS "  Embedded Tor:       ${USE_TOR_EMBEDDED}")
 message(STATUS "  Static linking:     ${ENABLE_STATIC}")
+message(STATUS "  ccache:             ${CCACHE_PROGRAM}")
+message(STATUS "  Unity build:        ${ENABLE_UNITY_BUILD}")
+message(STATUS "  Precompiled header: ON")
 message(STATUS "")

src/CMakeLists.txt

@@ -23,6 +23,8 @@ add_library(hash9_crypto STATIC
 )
 target_include_directories(hash9_crypto PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")
 set_target_properties(hash9_crypto PROPERTIES LINKER_LANGUAGE C)
+# Hash9 C files have colliding static symbols (IV512, DECL_STATE, etc.) — skip unity
+set_target_properties(hash9_crypto PROPERTIES UNITY_BUILD OFF)
 
 # ═══════════════════════════════════════════════════════════════════════════════
 # 2. JSON library (header-only nlohmann/json via json_compat.h shim)
@@ -72,6 +74,7 @@ set(CORE_SOURCES
     rpcsmessage.cpp
     zmqpublishnotifier.cpp
     txdb-leveldb.cpp
+    utxosnapshot.cpp
     lz4/lz4.c
     tor/onion_v3.cpp
     tor/tor_process.cpp
@@ -184,6 +187,31 @@ endif()
 
 add_dependencies(triangles_common generate_build_info build_leveldb)
 
+# ── Precompiled header (heavy STL + Boost + OpenSSL includes, C++ only) ──
+target_precompile_headers(triangles_common PRIVATE
+    "$<$<COMPILE_LANGUAGE:CXX>:<string$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<vector$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<map$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<deque$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<algorithm$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<sstream$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<stdexcept$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<cstdint$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<cstring$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<memory$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<functional$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/filesystem.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/filesystem/fstream.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread/mutex.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/thread/condition_variable.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<boost/algorithm/string.hpp$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/sha.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/crypto.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/rand.h$<ANGLE-R>>"
+    "$<$<COMPILE_LANGUAGE:CXX>:<openssl/evp.h$<ANGLE-R>>"
+)
+
 # ═══════════════════════════════════════════════════════════════════════════════
 # 4. Headless daemon (trianglesd)
 # ═══════════════════════════════════════════════════════════════════════════════
@@ -195,6 +223,7 @@ if(BUILD_DAEMON)
     )
     # No QT_GUI define — daemon gets the #if !defined(QT_GUI) code paths
     target_link_libraries(trianglesd PRIVATE triangles_common)
+    target_precompile_headers(trianglesd REUSE_FROM triangles_common)
 
     if(WIN32)
         set_target_properties(trianglesd PROPERTIES SUFFIX ".exe")

src/bootstrap.cpp

@@ -2,6 +2,7 @@
 // Distributed under the MIT/X11 software license
 
 #include "bootstrap.h"
+#include "utxosnapshot.h"
 
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
@@ -14,6 +15,9 @@
 #include "netbase.h"
 #include "net.h"
 
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+
 #include <fstream>
 #include <sstream>
 #include <cstdio>
@@ -42,34 +46,6 @@ bool NeedsBootstrap(const fs::path& dataDir)
     return !fs::exists(dataDir / "blk0001.dat");
 }
 
-// Send all bytes on a raw socket
-static bool SendAll(SOCKET sock, const char* data, size_t len)
-{
-    while (len > 0) {
-        int n = send(sock, data, (int)std::min(len, (size_t)65536), MSG_NOSIGNAL);
-        if (n <= 0) return false;
-        data += n;
-        len -= n;
-    }
-    return true;
-}
-
-// Read until `delim` found in received data. Returns data including delimiter.
-static bool RecvUntil(SOCKET sock, std::string& out, const std::string& delim)
-{
-    out.clear();
-    char c;
-    while (true) {
-        int n = recv(sock, &c, 1, 0);
-        if (n <= 0) return false;
-        out += c;
-        if (out.size() >= delim.size() &&
-            out.compare(out.size() - delim.size(), delim.size(), delim) == 0)
-            return true;
-        if (out.size() > 64 * 1024) return false; // header too large
-    }
-}
-
 // Direct TCP connection bypassing Tor SOCKS proxy.
 // Used for bootstrap downloads where the server is on clearnet.
 static SOCKET ConnectDirectTCP(const std::string& host, int port, std::string& strError)
@@ -106,6 +82,128 @@ static SOCKET ConnectDirectTCP(const std::string& host, int port, std::string& s
     return hSocket;
 }
 
+// RAII wrapper for an HTTP(S) connection (socket + optional TLS)
+struct HttpConn {
+    SOCKET sock;
+    SSL_CTX* ctx;
+    SSL* ssl;
+
+    HttpConn() : sock(INVALID_SOCKET), ctx(nullptr), ssl(nullptr) {}
+    ~HttpConn() { Close(); }
+
+    void Close() {
+        if (ssl)  { SSL_shutdown(ssl); SSL_free(ssl); ssl = nullptr; }
+        if (ctx)  { SSL_CTX_free(ctx); ctx = nullptr; }
+        if (sock != INVALID_SOCKET) { closesocket(sock); sock = INVALID_SOCKET; }
+    }
+
+    bool Send(const char* data, size_t len) {
+        while (len > 0) {
+            int n = ssl ? SSL_write(ssl, data, (int)std::min(len, (size_t)65536))
+                        : send(sock, data, (int)std::min(len, (size_t)65536), MSG_NOSIGNAL);
+            if (n <= 0) return false;
+            data += n;
+            len -= n;
+        }
+        return true;
+    }
+
+    int Recv(char* buf, int len) {
+        return ssl ? SSL_read(ssl, buf, len) : recv(sock, buf, len, 0);
+    }
+
+    // Read until delimiter found. Returns data including delimiter.
+    bool RecvUntil(std::string& out, const std::string& delim) {
+        out.clear();
+        char c;
+        while (true) {
+            int n = Recv(&c, 1);
+            if (n <= 0) return false;
+            out += c;
+            if (out.size() >= delim.size() &&
+                out.compare(out.size() - delim.size(), delim.size(), delim) == 0)
+                return true;
+            if (out.size() > 64 * 1024) return false; // header too large
+        }
+    }
+
+    // Establish TLS on an already-connected socket
+    bool StartTLS(const std::string& hostname, std::string& strError) {
+        ctx = SSL_CTX_new(TLS_client_method());
+        if (!ctx) {
+            strError = "Failed to create SSL context";
+            return false;
+        }
+        // Skip cert verification — we verify data integrity via checkpoint hashes
+        SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, nullptr);
+
+        ssl = SSL_new(ctx);
+        if (!ssl) {
+            strError = "Failed to create SSL object";
+            return false;
+        }
+        SSL_set_fd(ssl, (int)sock);
+        SSL_set_tlsext_host_name(ssl, hostname.c_str()); // SNI
+
+        if (SSL_connect(ssl) != 1) {
+            unsigned long err = ERR_get_error();
+            char errBuf[256];
+            ERR_error_string_n(err, errBuf, sizeof(errBuf));
+            strError = "TLS handshake failed with " + hostname + ": " + errBuf;
+            return false;
+        }
+        return true;
+    }
+};
+
+// Parse host, port, and path from an absolute URL.
+// Sets useSSL, host, port, path. Returns false for unsupported schemes.
+static bool ParseAbsoluteUrl(const std::string& url,
+                              bool& useSSL, std::string& host,
+                              int& port, std::string& path)
+{
+    if (url.compare(0, 8, "https://") == 0) {
+        useSSL = true;
+        std::string rest = url.substr(8);
+        size_t pathStart = rest.find('/');
+        if (pathStart != std::string::npos) {
+            host = rest.substr(0, pathStart);
+            path = rest.substr(pathStart);
+        } else {
+            host = rest;
+            path = "/";
+        }
+        size_t colonPos = host.find(':');
+        if (colonPos != std::string::npos) {
+            port = std::atoi(host.c_str() + colonPos + 1);
+            host = host.substr(0, colonPos);
+        } else {
+            port = 443;
+        }
+        return true;
+    } else if (url.compare(0, 7, "http://") == 0) {
+        useSSL = false;
+        std::string rest = url.substr(7);
+        size_t pathStart = rest.find('/');
+        if (pathStart != std::string::npos) {
+            host = rest.substr(0, pathStart);
+            path = rest.substr(pathStart);
+        } else {
+            host = rest;
+            path = "/";
+        }
+        size_t colonPos = host.find(':');
+        if (colonPos != std::string::npos) {
+            port = std::atoi(host.c_str() + colonPos + 1);
+            host = host.substr(0, colonPos);
+        } else {
+            port = 80;
+        }
+        return true;
+    }
+    return false;
+}
+
 bool DownloadFile(const std::string& host, const std::string& urlPath,
                   const fs::path& destPath,
                   ProgressCallback progressFn,
@@ -115,25 +213,38 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
     try {
         std::string currentHost = host;
         std::string currentPath = urlPath;
-        SOCKET hSocket = INVALID_SOCKET;
+        int currentPort = PORT;
+        bool useSSL = false;
         std::string headerData;
         int redirectCount = 0;
         const int MAX_REDIRECTS = 5;
 
+        HttpConn conn;
+
         // Connection + redirect loop
         while (true) {
+            conn.Close(); // clean slate for each attempt
+
             if (noProxy) {
-                hSocket = ConnectDirectTCP(currentHost, PORT, strError);
-                if (hSocket == INVALID_SOCKET)
+                conn.sock = ConnectDirectTCP(currentHost, currentPort, strError);
+                if (conn.sock == INVALID_SOCKET)
                     return false;
             } else {
                 CService addr;
-                if (!ConnectSocketByName(addr, hSocket, currentHost.c_str(), PORT, 30)) {
+                if (!ConnectSocketByName(addr, conn.sock, currentHost.c_str(), currentPort, 30)) {
                     strError = "Cannot connect to " + currentHost + " (check Tor proxy)";
                     return false;
                 }
             }
 
+            // Establish TLS when needed
+            if (useSSL) {
+                if (!conn.StartTLS(currentHost, strError))
+                    return false;
+                printf("Bootstrap: TLS established with %s:%d\n",
+                       currentHost.c_str(), currentPort);
+            }
+
             // Send HTTP GET request
             std::string request =
                 "GET " + currentPath + " HTTP/1.1\r\n"
@@ -142,15 +253,13 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
                 "User-Agent: Triangles\r\n"
                 "\r\n";
 
-            if (!SendAll(hSocket, request.data(), request.size())) {
-                closesocket(hSocket);
+            if (!conn.Send(request.data(), request.size())) {
                 strError = "Failed to send request to " + currentHost;
                 return false;
             }
 
             // Read response headers
-            if (!RecvUntil(hSocket, headerData, "\r\n\r\n")) {
-                closesocket(hSocket);
+            if (!conn.RecvUntil(headerData, "\r\n\r\n")) {
                 strError = "Failed to read HTTP headers from " + currentHost;
                 return false;
             }
@@ -164,8 +273,6 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
             // Handle HTTP redirects
             if (status_code == 301 || status_code == 302 ||
                 status_code == 307 || status_code == 308) {
-                closesocket(hSocket);
-                hSocket = INVALID_SOCKET;
 
                 if (++redirectCount > MAX_REDIRECTS) {
                     strError = "Too many redirects for " + urlPath;
@@ -193,28 +300,14 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
                     location = headerData.substr(valStart);
                 boost::trim(location);
 
-                // Reject HTTPS redirects (no TLS support)
-                if (location.compare(0, 8, "https://") == 0) {
-                    strError = "Server redirected to HTTPS (not supported). "
-                              "Configure bootstrap server for plain HTTP.";
-                    return false;
-                }
-
-                // Parse redirect URL
-                if (location.compare(0, 7, "http://") == 0) {
-                    std::string rest = location.substr(7);
-                    size_t pathStart = rest.find('/');
-                    if (pathStart != std::string::npos) {
-                        currentHost = rest.substr(0, pathStart);
-                        currentPath = rest.substr(pathStart);
-                    } else {
-                        currentHost = rest;
-                        currentPath = "/";
+                // Parse redirect URL — supports http://, https://, and relative paths
+                if (location.compare(0, 7, "http://") == 0 ||
+                    location.compare(0, 8, "https://") == 0) {
+                    if (!ParseAbsoluteUrl(location, useSSL, currentHost,
+                                          currentPort, currentPath)) {
+                        strError = "Unsupported redirect location: " + location;
+                        return false;
                     }
-                    // Strip port from host if present
-                    size_t colonPos = currentHost.find(':');
-                    if (colonPos != std::string::npos)
-                        currentHost = currentHost.substr(0, colonPos);
                 } else if (!location.empty() && location[0] == '/') {
                     currentPath = location;
                 } else {
@@ -222,13 +315,13 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
                     return false;
                 }
 
-                printf("Bootstrap: redirect %d -> %s%s\n",
-                       status_code, currentHost.c_str(), currentPath.c_str());
+                printf("Bootstrap: redirect %d -> %s%s%s (port %d)\n",
+                       status_code, useSSL ? "https://" : "http://",
+                       currentHost.c_str(), currentPath.c_str(), currentPort);
                 continue;
             }
 
             if (status_code != 200) {
-                closesocket(hSocket);
                 strError = "HTTP error " + std::to_string(status_code) + " for " + currentPath;
                 return false;
             }
@@ -252,7 +345,6 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
         // Open output file
         FILE* file = fopen(destPath.string().c_str(), "wb");
         if (!file) {
-            closesocket(hSocket);
             strError = "Cannot create file: " + destPath.string();
             return false;
         }
@@ -263,10 +355,9 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
         char chunk[65536];
 
         while (true) {
-            int n = recv(hSocket, chunk, sizeof(chunk), 0);
+            int n = conn.Recv(chunk, sizeof(chunk));
             if (n < 0) {
                 fclose(file);
-                closesocket(hSocket);
                 fs::remove(destPath);
                 strError = "Network error during download";
                 return false;
@@ -283,7 +374,7 @@ bool DownloadFile(const std::string& host, const std::string& urlPath,
         }
 
         fclose(file);
-        closesocket(hSocket);
+        // conn destructor handles socket + SSL cleanup
 
         // Verify download size if Content-Length was provided
         if (content_length > 0 && bytes_written != content_length) {
@@ -676,4 +767,38 @@ bool DownloadBootstrap(const std::string& host,
     return true;
 }
 
+bool DownloadUtxoSnapshot(const std::string& host,
+                          const fs::path& dataDir,
+                          ProgressCallback progressFn,
+                          std::string& strError)
+{
+    const bool noProxy = true;
+    const char* snapshotFilename = "utxo-snapshot.bin";
+
+    // Download utxo-snapshot.bin to a temp file
+    fs::path tmpPath = dataDir / "utxo-snapshot.bin.tmp";
+    std::string urlPath = std::string(BASE_PATH) + snapshotFilename;
+
+    printf("Bootstrap: downloading UTXO snapshot from %s%s...\n", host.c_str(), urlPath.c_str());
+
+    if (!DownloadFile(host, urlPath, tmpPath, progressFn, strError, noProxy)) {
+        fs::remove(tmpPath);
+        return false;
+    }
+
+    printf("Bootstrap: UTXO snapshot downloaded, loading into database...\n");
+
+    // Load the snapshot into a fresh txleveldb
+    if (!UtxoSnapshot::LoadSnapshot(tmpPath, dataDir, strError)) {
+        fs::remove(tmpPath);
+        return false;
+    }
+
+    // Clean up the temp file
+    fs::remove(tmpPath);
+
+    printf("Bootstrap: UTXO snapshot loaded successfully.\n");
+    return true;
+}
+
 } // namespace Bootstrap

src/bootstrap.h

@@ -62,6 +62,14 @@ namespace Bootstrap {
     bool VerifyManifest(const SnapshotManifest& manifest,
                         std::string& strError);
 
+    // Download a UTXO snapshot and load it into a fresh txleveldb.
+    // This is much faster than downloading the full bootstrap archive.
+    // Returns true if snapshot was downloaded and loaded successfully.
+    bool DownloadUtxoSnapshot(const std::string& host,
+                              const boost::filesystem::path& dataDir,
+                              ProgressCallback progressFn,
+                              std::string& strError);
+
 } // namespace Bootstrap
 
 #endif // TRIANGLES_BOOTSTRAP_H

src/checkpoints.cpp

@@ -36,6 +36,10 @@ namespace Checkpoints
         {2190000, uint256("0x682baf783581468ba18f9967254a7f3944e8b8c4cc7101e7d99b68f4f9dd5271")},
         {2200000, uint256("0x0a8d0442f031f1258120f713f34e45f4f9a625fb753558e27b89b32ad5a9a740")},
         {2205000, uint256("0xf7aa893ec012181e321783d6a5487addf6997377908faa3e760c9054a4217d29")},
+        {2206000, uint256("0x780ae878f8b10b6cbd51ceb2c0799c90d3551fa916be62974375071b9e36581c")},
+        {2207000, uint256("0x8836d67b0f08036c4a7c26ff0a29d4461a52b6d8f552165ad9c1abec2f3cadfd")},
+        {2208000, uint256("0xe4a19e8a29fa7aae47f7563377af3e896fee18ed069a64e325b8c2c6c820a1be")},
+        {2209000, uint256("0x04c78a6fc863bed918a9364c58c64489943b2e85d84ddb1ac2fba584f390d5dc")},
     };
 
     static MapCheckpoints mapCheckpointsTestnet = {
@@ -55,6 +59,10 @@ namespace Checkpoints
         {2190000, uint256("0x682baf783581468ba18f9967254a7f3944e8b8c4cc7101e7d99b68f4f9dd5271")},
         {2200000, uint256("0x0a8d0442f031f1258120f713f34e45f4f9a625fb753558e27b89b32ad5a9a740")},
         {2205000, uint256("0xf7aa893ec012181e321783d6a5487addf6997377908faa3e760c9054a4217d29")},
+        {2206000, uint256("0x780ae878f8b10b6cbd51ceb2c0799c90d3551fa916be62974375071b9e36581c")},
+        {2207000, uint256("0x8836d67b0f08036c4a7c26ff0a29d4461a52b6d8f552165ad9c1abec2f3cadfd")},
+        {2208000, uint256("0xe4a19e8a29fa7aae47f7563377af3e896fee18ed069a64e325b8c2c6c820a1be")},
+        {2209000, uint256("0x04c78a6fc863bed918a9364c58c64489943b2e85d84ddb1ac2fba584f390d5dc")},
     };
 
     bool CheckHardened(int nHeight, const uint256& hash)

src/clientversion.h

@@ -7,8 +7,8 @@
 
 // These need to be macros, as version.cpp's and triangles-qt.rc's voodoo requires it
 #define CLIENT_VERSION_MAJOR       5
-#define CLIENT_VERSION_MINOR       8
-#define CLIENT_VERSION_REVISION    3
+#define CLIENT_VERSION_MINOR       9
+#define CLIENT_VERSION_REVISION    0
 #define CLIENT_VERSION_BUILD       0
 
 // Converts the parameter X to a string after macro replacement on X has been performed.

src/init.cpp

@@ -14,6 +14,7 @@
 #include "smessage.h"
 #include "openssl_compat.h"
 #include "bootstrap.h"
+#include "utxosnapshot.h"
 #include "tor/tor_embedded.h"
 #include "tor/onion_v3.h"
 #include "tor/tor_process.h"
@@ -669,7 +670,7 @@ bool AppInit2()
         nScriptCheckThreads = 16;
     if (nScriptCheckThreads > 1)
     {
-        pScriptCheckQueue = new CCheckQueue<CScriptCheck>(128);
+        pScriptCheckQueue = new CCheckQueue<CScriptCheck>(32);
         pScriptCheckThreads = new boost::thread_group();
         for (int i = 0; i < nScriptCheckThreads - 1; ++i)
             pScriptCheckThreads->create_thread(&ThreadScriptCheck);
@@ -907,9 +908,6 @@ bool AppInit2()
         std::string host = Bootstrap::DEFAULT_HOST;
         std::string strError;
 
-        uiInterface.InitMessage(_("Downloading blockchain snapshot..."));
-        printf("Bootstrap: contacting %s...\n", host.c_str());
-
         auto progressFn = [](int64_t bytesDownloaded, int64_t totalBytes) {
             if (totalBytes > 0) {
                 printf("\rBootstrap: %lld / %lld MB (%lld%%)",
@@ -920,20 +918,66 @@ bool AppInit2()
             }
         };
 
-        bool success = Bootstrap::DownloadBootstrap(host, dataPath, progressFn, strError);
+        // Try UTXO snapshot first (fast: ~2-10 MB download)
+        bool success = false;
+        bool triedUtxoSnapshot = false;
+        if (needsBootstrap && !fs::exists(dataPath / "txleveldb")) {
+            uiInterface.InitMessage(_("Downloading UTXO snapshot..."));
+            printf("Bootstrap: trying UTXO snapshot from %s (fast path)...\n", host.c_str());
 
-        if (!success) {
-            printf("\nBootstrap: failed: %s\n", strError.c_str());
-            printf("Bootstrap: skipping, will sync from network.\n");
-        } else {
-            printf("\nBootstrap: done.\n");
+            std::string utxoError;
+            if (Bootstrap::DownloadUtxoSnapshot(host, dataPath, progressFn, utxoError)) {
+                printf("\nBootstrap: UTXO snapshot loaded — will sync remaining blocks from network.\n");
+                success = true;
+            } else {
+                printf("\nBootstrap: UTXO snapshot unavailable: %s\n", utxoError.c_str());
+                printf("Bootstrap: falling back to full bootstrap download...\n");
+            }
+            triedUtxoSnapshot = true;
         }
+
+        // Fall back to full bootstrap.tar.gz if UTXO snapshot failed
+        if (!success) {
+            uiInterface.InitMessage(_("Downloading blockchain snapshot..."));
+            printf("Bootstrap: contacting %s...\n", host.c_str());
+
+            success = Bootstrap::DownloadBootstrap(host, dataPath, progressFn, strError);
+
+            if (!success) {
+                printf("\nBootstrap: failed: %s\n", strError.c_str());
+                printf("Bootstrap: skipping, will sync from network.\n");
+            } else {
+                printf("\nBootstrap: done.\n");
+            }
+        }
+
         StartupPerfLog("bootstrap_download", GetTimeMillis() - nBootstrapStart,
-            strprintf("host=%s success=%d", host.c_str(), success));
+            strprintf("host=%s success=%d utxo_snapshot=%d", host.c_str(), success, triedUtxoSnapshot));
     }
     } // end bootstrap scope
 #endif
 
+    // ********************************************************* Step 6c: manual UTXO snapshot loading
+    // If utxo-snapshot.bin exists in data dir and no txleveldb, load it.
+    {
+        fs::path dataPath = GetDataDir();
+        fs::path snapshotFile = dataPath / "utxo-snapshot.bin";
+        fs::path txleveldbDir = dataPath / "txleveldb";
+
+        if (fs::exists(snapshotFile) && !fs::exists(txleveldbDir)) {
+            printf("Found utxo-snapshot.bin — loading UTXO snapshot...\n");
+            uiInterface.InitMessage(_("Loading UTXO snapshot..."));
+
+            std::string strError;
+            if (UtxoSnapshot::LoadSnapshot(snapshotFile, dataPath, strError)) {
+                printf("UTXO snapshot loaded successfully.\n");
+            } else {
+                printf("UTXO snapshot load failed: %s\n", strError.c_str());
+                printf("Will proceed with normal sync.\n");
+            }
+        }
+    }
+
     // ********************************************************* Step 7: load blockchain
 
     if (!bitdb.Open(GetDataDir()))

src/kernel.cpp

@@ -31,9 +31,13 @@ int64_t GetWeight(int64_t nIntervalBeginning, int64_t nIntervalEnd)
     if (nAge < 0)
         return 0;
 
-    // After v5 fork: remove max age cap so coins aged during the freeze can stake
+    // After v5 fork: use soft cap of 7 days instead of hard nStakeMaxAge.
+    // This prevents "stake surprise" where a whale who was offline for weeks
+    // comes back with massively amplified staking power and dominates blocks.
+    // The 7-day cap still allows generous accumulation while limiting abuse.
+    static const int64_t STAKE_AGE_SOFT_CAP = 7 * 24 * 60 * 60; // 7 days
     if (pindexBest && pindexBest->nHeight >= FORK_HEIGHT_V5)
-        return nAge;
+        return min(nAge, STAKE_AGE_SOFT_CAP);
 
     return min(nAge, (int64_t)nStakeMaxAge);
 }

src/main.h

@@ -12,6 +12,7 @@
 #include "scrypt.h"
 #include "hashblock.h"
 #include "checkqueue.h"
+#include "sigcache.h"
 
 #include <list>
 
@@ -37,8 +38,9 @@ static const unsigned int MAX_BLOCK_SIZE = 1000000;
 static const unsigned int MAX_BLOCK_SIZE_GEN = MAX_BLOCK_SIZE/2;
 static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
 static const unsigned int MAX_ORPHAN_TRANSACTIONS = MAX_BLOCK_SIZE/100;
-static const unsigned int MAX_ORPHAN_BLOCKS = 2000;
-static const unsigned int MAX_ORPHAN_BLOCKS_IBD = 4000;
+static const unsigned int MAX_ORPHAN_BLOCKS = 750;
+static const unsigned int MAX_ORPHAN_BLOCKS_IBD = 1500;
+static const unsigned int MAX_REORG_DEPTH = 100;  // reject reorgs deeper than this (finality)
 static const unsigned int MAX_INV_SZ = 50000;
 static const int64_t MIN_TX_FEE = (1 * CENT) / 100;
 static const int64_t MIN_RELAY_TX_FEE = (1 * CENT) / 100;
@@ -83,6 +85,7 @@ extern uint256 nBestChainTrust;
 extern uint256 nBestInvalidTrust;
 extern uint256 hashBestChain;
 extern CBlockIndex* pindexBest;
+extern CBlockIndex* pindexFinalized;  // auto-checkpoint: deepest finalized block
 extern unsigned int nTransactionsUpdated;
 extern uint64_t nLastBlockTx;
 extern uint64_t nLastBlockSize;
@@ -1560,6 +1563,12 @@ public:
         return vHave.empty();
     }
 
+    // Return the first hash in the locator (peer's tip), or 0 if empty
+    uint256 GetTipHash() const
+    {
+        return vHave.empty() ? uint256(0) : vHave[0];
+    }
+
     void Set(const CBlockIndex* pindex)
     {
         vHave.clear();
@@ -1679,6 +1688,121 @@ public:
 };
 
 extern CTxMemPool mempool;
+extern CScriptVerifyCache scriptVerifyCache;
+
+/**
+ * Compact block relay for Tor-only networks.
+ *
+ * Instead of sending a full block, send the header + short transaction IDs.
+ * The receiver reconstructs the block from its mempool.  For PoS blocks with
+ * 0-2 transactions (the common case), the coinstake is always prefilled, so
+ * the compact block IS the complete block — no extra round-trip needed.
+ */
+
+/** Short transaction ID: first 6 bytes of SipHash(txid) */
+static inline uint64_t GetShortTxId(const uint256& txhash, uint64_t nonce)
+{
+    // Simple short ID: XOR txhash prefix with nonce
+    uint64_t id = 0;
+    memcpy(&id, txhash.begin(), 6);  // first 6 bytes
+    id ^= nonce;
+    return id & 0xFFFFFFFFFFFFULL;  // mask to 48 bits
+}
+
+class CCompactBlock
+{
+public:
+    // Block header fields
+    int nVersion;
+    uint256 hashPrevBlock;
+    uint256 hashMerkleRoot;
+    unsigned int nTime;
+    unsigned int nBits;
+    unsigned int nNonce;
+    std::vector<unsigned char> vchBlockSig;
+
+    // Compact block data
+    uint64_t nShortIdNonce;                     // nonce for short ID calculation
+    std::vector<uint64_t> vShortTxIds;          // short IDs for non-prefilled txs
+    std::vector<std::pair<uint16_t, CTransaction>> vPrefilledTxn;  // index + full tx
+
+    CCompactBlock() : nVersion(0), nTime(0), nBits(0), nNonce(0), nShortIdNonce(0) {}
+
+    // Construct from a full block: prefill coinbase + coinstake, short-ID the rest
+    CCompactBlock(const CBlock& block)
+    {
+        nVersion = block.nVersion;
+        hashPrevBlock = block.hashPrevBlock;
+        hashMerkleRoot = block.hashMerkleRoot;
+        nTime = block.nTime;
+        nBits = block.nBits;
+        nNonce = block.nNonce;
+        vchBlockSig = block.vchBlockSig;
+        nShortIdNonce = GetRand(std::numeric_limits<uint64_t>::max());
+
+        for (uint16_t i = 0; i < block.vtx.size(); i++)
+        {
+            if (i <= 1) {
+                // Always prefill coinbase (idx 0) and coinstake (idx 1)
+                vPrefilledTxn.push_back(std::make_pair(i, block.vtx[i]));
+            } else {
+                vShortTxIds.push_back(GetShortTxId(block.vtx[i].GetHash(), nShortIdNonce));
+            }
+        }
+    }
+
+    IMPLEMENT_SERIALIZE
+    (
+        READWRITE(nVersion);
+        READWRITE(hashPrevBlock);
+        READWRITE(hashMerkleRoot);
+        READWRITE(nTime);
+        READWRITE(nBits);
+        READWRITE(nNonce);
+        READWRITE(vchBlockSig);
+        READWRITE(nShortIdNonce);
+        READWRITE(vShortTxIds);
+        READWRITE(vPrefilledTxn);
+    )
+
+    uint256 GetBlockHash() const
+    {
+        CBlock hdr;
+        hdr.nVersion = nVersion;
+        hdr.hashPrevBlock = hashPrevBlock;
+        hdr.hashMerkleRoot = hashMerkleRoot;
+        hdr.nTime = nTime;
+        hdr.nBits = nBits;
+        hdr.nNonce = nNonce;
+        return hdr.GetHash();
+    }
+};
+
+class CBlockTxnRequest
+{
+public:
+    uint256 blockhash;
+    std::vector<uint16_t> vIndex;  // indices of missing transactions
+
+    IMPLEMENT_SERIALIZE
+    (
+        READWRITE(blockhash);
+        READWRITE(vIndex);
+    )
+};
+
+class CBlockTxnResponse
+{
+public:
+    uint256 blockhash;
+    std::vector<CTransaction> vTxn;
+
+    IMPLEMENT_SERIALIZE
+    (
+        READWRITE(blockhash);
+        READWRITE(vTxn);
+    )
+};
 
 /**
  * Closure representing one script check for parallel verification.
@@ -1703,7 +1827,12 @@ public:
 
     bool operator()()
     {
-        return ptxTo && VerifyScript(scriptSig, scriptPubKey, *ptxTo, nIn, nHashType);
+        if (!ptxTo)
+            return false;
+        if (!VerifyScript(scriptSig, scriptPubKey, *ptxTo, nIn, nHashType))
+            return false;
+        scriptVerifyCache.Set(ptxTo->GetHash(), nIn);
+        return true;
     }
 
     void swap(CScriptCheck& other)

src/miner.cpp

@@ -446,9 +446,20 @@ void StakeMiner(CWallet *pwallet)
         {
             printf("StakeMiner(): A proof-of-stake block has been found! %s\n", pblock->GetHash().ToString().c_str());
             SetThreadPriority(THREAD_PRIORITY_NORMAL);
-            CheckStake(pblock.get(), *pwallet);
+            bool fAccepted = CheckStake(pblock.get(), *pwallet);
             SetThreadPriority(THREAD_PRIORITY_LOWEST);
-            MilliSleep(500);
+            if (fAccepted)
+            {
+                MilliSleep(500);
+            }
+            else
+            {
+                // Block was orphaned or rejected — apply a cooldown to reduce
+                // fork oscillation. Without this, the staker immediately retries
+                // with a different timestamp, potentially creating competing forks.
+                printf("StakeMiner(): block not accepted, cooldown 30s\n");
+                MilliSleep(30000);
+            }
         }
         else
           MilliSleep(500);

src/net.cpp

@@ -37,7 +37,7 @@ extern "C" {
 // int tor_main(int argc, char *argv[]);
 }
 
-static const int MAX_OUTBOUND_CONNECTIONS = 16;
+static const int MAX_OUTBOUND_CONNECTIONS = 8;  // reduced from 16 for Tor-only small networks
 
 void ThreadMessageHandler2(void* parg);
 void ThreadSocketHandler2(void* parg);
@@ -47,7 +47,7 @@ void ThreadOpenAddedConnections2(void* parg);
 void ThreadMapPort2(void* parg);
 #endif
 void ThreadHTTPSeedFetch(void* parg);
-void ThreadHTTPSeedFetch2(void* parg);
+bool ThreadHTTPSeedFetch2(void* parg);
 bool OpenNetworkConnection(const CAddress& addrConnect, CSemaphoreGrant *grantOutbound = NULL, const char *strDest = NULL, bool fOneShot = false);
 
 
@@ -690,6 +690,9 @@ void CNode::copyStats(CNodeStats &stats)
     X(fInbound);
     X(nStartingHeight);
     X(nMisbehavior);
+    X(nPingUsecTime);
+    X(nBlocksDelivered);
+    X(nAvgBlockLatencyUs);
 }
 #undef X
 
@@ -1029,10 +1032,6 @@ void ThreadSocketHandler2(void* parg)
                 if (nErr != WSAEWOULDBLOCK)
                     printf("socket error accept failed: %d\n", nErr);
             }
-            else if (nInbound >= GetArg("-maxconnections", 125) - MAX_OUTBOUND_CONNECTIONS)
-            {
-                closesocket(hSocket);
-            }
             else if (CNode::IsBanned(addr))
             {
                 printf("connection from %s dropped (banned)\n", addr.ToString().c_str());
@@ -1040,12 +1039,36 @@ void ThreadSocketHandler2(void* parg)
             }
             else
             {
-                printf("accepted connection %s\n", addr.ToString().c_str());
-                CNode* pnode = new CNode(hSocket, addr, "", true);
-                pnode->AddRef();
-                {
-                    LOCK(cs_vNodes);
-                    vNodes.push_back(pnode);
+                int nMaxInbound = GetArg("-maxconnections", 125) - MAX_OUTBOUND_CONNECTIONS;
+                bool fAccept = (nInbound < nMaxInbound);
+
+                // Reserve 2 extra inbound slots for known seed nodes
+                if (!fAccept) {
+                    bool fIsSeed = false;
+                    static const char *(*strOnionSeedCheck)[1] = fTestNet ? strTestNetOnionSeed : strMainNetOnionSeed;
+                    std::string incomingAddr = addr.ToStringIP();
+                    for (unsigned int si = 0; strOnionSeedCheck[si][0] != NULL; si++) {
+                        if (incomingAddr.find(strOnionSeedCheck[si][0]) != std::string::npos) {
+                            fIsSeed = true;
+                            break;
+                        }
+                    }
+                    if (fIsSeed && nInbound < nMaxInbound + 2) {
+                        fAccept = true;
+                        printf("accepted seed node %s (reserved slot)\n", addr.ToString().c_str());
+                    }
+                }
+
+                if (fAccept) {
+                    printf("accepted connection %s\n", addr.ToString().c_str());
+                    CNode* pnode = new CNode(hSocket, addr, "", true);
+                    pnode->AddRef();
+                    {
+                        LOCK(cs_vNodes);
+                        vNodes.push_back(pnode);
+                    }
+                } else {
+                    closesocket(hSocket);
                 }
             }
         }
@@ -1137,14 +1160,14 @@ void ThreadSocketHandler2(void* parg)
                     printf("socket no message in first 60 seconds, %d %d\n", pnode->nLastRecv != 0, pnode->nLastSend != 0);
                     pnode->fDisconnect = true;
                 }
-                else if (GetTime() - pnode->nLastSend > 90*60 && GetTime() - pnode->nLastSendEmpty > 90*60)
+                else if (GetTime() - pnode->nLastSend > 10*60 && GetTime() - pnode->nLastSendEmpty > 10*60)
                 {
-                    printf("socket not sending\n");
+                    printf("socket not sending (10min timeout)\n");
                     pnode->fDisconnect = true;
                 }
-                else if (GetTime() - pnode->nLastRecv > 90*60)
+                else if (GetTime() - pnode->nLastRecv > 10*60)
                 {
-                    printf("socket inactivity timeout\n");
+                    printf("socket inactivity timeout (10min)\n");
                     pnode->fDisconnect = true;
                 }
             }
@@ -1381,7 +1404,7 @@ void ThreadOnionSeed(void* parg)
 
 
 
-    // Load hardcoded .onion seeds (if any)
+    // Load hardcoded .onion seeds and queue them for immediate direct connection
     static const char *(*strOnionSeed)[1] = fTestNet ? strTestNetOnionSeed : strMainNetOnionSeed;
     int found = 0;
 
@@ -1394,27 +1417,50 @@ void ThreadOnionSeed(void* parg)
         CAddress addr = CAddress(CService(parsed, GetDefaultPort()));
         addr.nTime = GetTime() - 3*nOneDay - GetRand(4*nOneDay);
         addrman.Add(addr, parsed);
+
+        // Queue for immediate direct connection (OneShot) — don't wait for
+        // addrman selection which deprioritizes stale timestamps
+        std::string oneShotAddr = std::string(strOnionSeed[seed_idx][0])
+                                + ":" + std::to_string(GetDefaultPort());
+        AddOneShot(oneShotAddr);
         found++;
     }
 
-    printf("%d addresses from hardcoded .onion seeds\n", found);
+    printf("%d addresses from hardcoded .onion seeds (queued as OneShot)\n", found);
 
-    // Also fetch dynamic seeds from HTTP seed list
+    // Wait for Tor to establish circuits before attempting HTTPS seed fetch.
+    // The hardcoded OneShot connections can race ahead meanwhile.
+    printf("ThreadOnionSeed: waiting 20s for Tor circuits before HTTPS seed fetch...\n");
+    for (int i = 0; i < 20 && !fShutdown; i++)
+        MilliSleep(1000);
+
+    // Fetch dynamic seeds with retry — up to 4 attempts with increasing backoff.
     // This is the primary discovery mechanism — seeds.cryptographic-triangles.org
-    ThreadHTTPSeedFetch2(NULL);
+    {
+        bool ok = false;
+        int delays[] = {0, 30, 60, 120};
+        for (int attempt = 0; attempt < 4 && !ok && !fShutdown; attempt++) {
+            if (attempt > 0) {
+                printf("ThreadOnionSeed: HTTPS seed fetch retry %d in %ds...\n", attempt, delays[attempt]);
+                for (int i = 0; i < delays[attempt] && !fShutdown; i++)
+                    MilliSleep(1000);
+            }
+            if (!fShutdown)
+                ok = ThreadHTTPSeedFetch2(NULL);
+        }
+        if (!ok && !fShutdown)
+            printf("ThreadOnionSeed: all HTTPS seed fetch attempts failed\n");
+    }
 
     printf("ThreadOnionSeed: initial seeding complete\n");
 
-    // Periodic re-seeding: if the node becomes isolated (0 outbound peers),
-    // re-fetch the seed list. Check every 10 minutes, re-seed at most once
-    // per 30 minutes to avoid hammering the seed server.
+    // Periodic re-seeding for isolated or under-connected nodes.
+    // EMERGENCY MODE: When 0 outbound peers, check every 15 seconds
+    // NORMAL MODE: Check every 2 minutes, re-seed when < 2 outbound peers
     int64_t nLastReseed = GetTime();
+    bool bFirstReseed = true;
     while (!fShutdown) {
-        for (int i = 0; i < 600 && !fShutdown; i++) // sleep 10 minutes
-            MilliSleep(1000);
-
-        if (fShutdown) break;
-
+        // Count outbound peers to determine check interval
         int nOutbound = 0;
         {
             LOCK(cs_vNodes);
@@ -1423,10 +1469,52 @@ void ThreadOnionSeed(void* parg)
                     nOutbound++;
         }
 
-        if (nOutbound == 0 && GetTime() - nLastReseed > 30 * 60) {
-            printf("ThreadOnionSeed: no outbound peers, re-seeding...\n");
+        // Emergency mode: 0 peers = check every 15 seconds
+        // Low mode: 1 peer = check every 30 seconds
+        // Normal: 2+ peers = check every 2 minutes
+        int nSleepSeconds = (nOutbound == 0) ? 15 : (nOutbound < 2) ? 30 : 120;
+        for (int i = 0; i < nSleepSeconds && !fShutdown; i++)
+            MilliSleep(1000);
+
+        if (fShutdown) break;
+
+        // Recount after sleep
+        nOutbound = 0;
+        {
+            LOCK(cs_vNodes);
+            for (CNode* pnode : vNodes)
+                if (!pnode->fInbound)
+                    nOutbound++;
+        }
+
+        // Emergency (0 peers): no cooldown, reseed immediately
+        // Low (1 peer): 60 second cooldown
+        // Normal (<2): 5 min first, 15 min subsequent
+        int64_t nCooldown;
+        if (nOutbound == 0)
+            nCooldown = 0;  // immediate
+        else if (nOutbound < 2)
+            nCooldown = bFirstReseed ? 60 : 5 * 60;
+        else
+            nCooldown = bFirstReseed ? 5 * 60 : 15 * 60;
+
+        if (nOutbound < 2 && GetTime() - nLastReseed > nCooldown) {
+            if (nOutbound == 0)
+                printf("ThreadOnionSeed: EMERGENCY - 0 outbound peers, re-seeding immediately!\n");
+            else
+                printf("ThreadOnionSeed: low outbound peers (%d), re-seeding...\n", nOutbound);
+
             ThreadHTTPSeedFetch2(NULL);
+
+            // Re-queue hardcoded seeds for direct connection
+            for (unsigned int seed_idx = 0; strOnionSeed[seed_idx][0] != NULL; seed_idx++) {
+                std::string oneShotAddr = std::string(strOnionSeed[seed_idx][0])
+                                        + ":" + std::to_string(GetDefaultPort());
+                AddOneShot(oneShotAddr);
+            }
+
             nLastReseed = GetTime();
+            bFirstReseed = false;
         }
     }
 }
@@ -1486,7 +1574,7 @@ void ThreadDumpAddress(void* parg)
     printf("ThreadDumpAddress exited\n");
 }
 
-void ThreadHTTPSeedFetch2(void* parg)
+bool ThreadHTTPSeedFetch2(void* parg)
 {
     static const char* DEFAULT_SEED_URL_HOST = "seeds.cryptographic-triangles.org";
     static const char* DEFAULT_SEED_URL_PATH = "/seeds.txt";
@@ -1515,7 +1603,7 @@ void ThreadHTTPSeedFetch2(void* parg)
 
         if (!ConnectSocketByName(addrResolved, hSocket, connectDest.c_str(), HTTPS_PORT, nConnectTimeout)) {
             printf("HTTPS seed fetch: cannot connect to %s through Tor proxy\n", seedHost.c_str());
-            return;
+            return false;
         }
 
         // Set up TLS over the connected socket
@@ -1523,7 +1611,7 @@ void ThreadHTTPSeedFetch2(void* parg)
         if (!ctx) {
             printf("HTTPS seed fetch: SSL_CTX_new failed\n");
             closesocket(hSocket);
-            return;
+            return false;
         }
 
         // Use system default CA certificates for verification
@@ -1535,7 +1623,7 @@ void ThreadHTTPSeedFetch2(void* parg)
             printf("HTTPS seed fetch: SSL_new failed\n");
             SSL_CTX_free(ctx);
             closesocket(hSocket);
-            return;
+            return false;
         }
 
         // Set SNI hostname (required for Caddy/Let's Encrypt)
@@ -1552,7 +1640,7 @@ void ThreadHTTPSeedFetch2(void* parg)
             SSL_free(ssl);
             SSL_CTX_free(ctx);
             closesocket(hSocket);
-            return;
+            return false;
         }
 
         printf("HTTPS seed fetch: TLS connection established to %s\n", seedHost.c_str());
@@ -1575,7 +1663,7 @@ void ThreadHTTPSeedFetch2(void* parg)
                 SSL_free(ssl);
                 SSL_CTX_free(ctx);
                 closesocket(hSocket);
-                return;
+                return false;
             }
             nSent += nBytes;
         }
@@ -1600,21 +1688,21 @@ void ThreadHTTPSeedFetch2(void* parg)
 
         if (response.empty()) {
             printf("HTTPS seed fetch: empty response from %s\n", seedHost.c_str());
-            return;
+            return false;
         }
 
         // Parse HTTP response - find end of headers
         size_t headerEnd = response.find("\r\n\r\n");
         if (headerEnd == std::string::npos) {
             printf("HTTPS seed fetch: malformed response (no header terminator)\n");
-            return;
+            return false;
         }
 
         // Check status code
         std::string statusLine = response.substr(0, response.find("\r\n"));
         if (statusLine.find("200") == std::string::npos) {
             printf("HTTPS seed fetch: %s from %s\n", statusLine.c_str(), seedHost.c_str());
-            return;
+            return false;
         }
 
         std::string body = response.substr(headerEnd + 4);
@@ -1626,7 +1714,7 @@ void ThreadHTTPSeedFetch2(void* parg)
         while (std::getline(lines, line))
         {
             if (fShutdown)
-                return;
+                return false;
 
             // Trim whitespace and carriage returns
             while (!line.empty() && (line.back() == '\r' || line.back() == ' ' || line.back() == '\t'))
@@ -1667,17 +1755,24 @@ void ThreadHTTPSeedFetch2(void* parg)
                 CAddress addr(CService(parsed, port));
                 addr.nTime = GetTime() - 3*24*60*60; // 3 days ago
                 addrman.Add(addr, CNetAddr("https-seed", true));
+                // Queue the first 8 seeds for immediate direct connection
+                if (found < 8) {
+                    std::string oneShotAddr = addrStr + ":" + std::to_string(port);
+                    AddOneShot(oneShotAddr);
+                }
                 found++;
             }
         }
 
         printf("%d addresses found from HTTPS seed list (%s)\n", found, seedHost.c_str());
+        return found > 0;
 
     } catch (std::exception& e) {
         printf("HTTPS seed fetch failed: %s\n", e.what());
         if (ssl) { SSL_shutdown(ssl); SSL_free(ssl); }
         if (ctx) SSL_CTX_free(ctx);
         if (hSocket != INVALID_SOCKET) closesocket(hSocket);
+        return false;
     }
 }
 
@@ -2297,8 +2392,11 @@ void StartNode(void* parg)
     RenameThread("Triangles-start");
 
     if (semOutbound == NULL) {
-        // initialize semaphore
-        int nMaxOutbound = min(MAX_OUTBOUND_CONNECTIONS, (int)GetArg("-maxconnections", 125));
+        // initialize semaphore — use -maxoutbound if specified, else default
+        int nMaxOutbound = (int)GetArg("-maxoutbound", MAX_OUTBOUND_CONNECTIONS);
+        nMaxOutbound = min(nMaxOutbound, (int)GetArg("-maxconnections", 125));
+        nMaxOutbound = max(nMaxOutbound, 1);  // at least 1 outbound
+        printf("Max outbound connections: %d\n", nMaxOutbound);
         semOutbound = new CSemaphore(nMaxOutbound);
     }
 
@@ -2368,9 +2466,13 @@ bool StopNode()
     fShutdown = true;
     nTransactionsUpdated++;
     int64_t nStart = GetTime();
-    if (semOutbound)
-        for (int i=0; i<MAX_OUTBOUND_CONNECTIONS; i++)
+    if (semOutbound) {
+        int nMaxOutbound = (int)GetArg("-maxoutbound", MAX_OUTBOUND_CONNECTIONS);
+        nMaxOutbound = min(nMaxOutbound, (int)GetArg("-maxconnections", 125));
+        nMaxOutbound = max(nMaxOutbound, 1);
+        for (int i=0; i<nMaxOutbound; i++)
             semOutbound->post();
+    }
     do
     {
         int nThreadsRunning = 0;

src/net.h

@@ -26,7 +26,7 @@ extern int nBestHeight;
 
 
 
-inline unsigned int ReceiveFloodSize() { return 100 * 1024 * 1024; } // 100 MB
+inline unsigned int ReceiveFloodSize() { return 50 * 1024 * 1024; }  // 50 MB (reduced for Tor-only network)
 inline unsigned int SendBufferSize() { return 32 * 1024 * 1024; }   // 32 MB
 
 void AddOneShot(std::string strDest);
@@ -146,6 +146,9 @@ public:
     bool fInbound;
     int nStartingHeight;
     int nMisbehavior;
+    int64_t nPingUsecTime;
+    int nBlocksDelivered;
+    int64_t nAvgBlockLatencyUs;
 };
 
 
@@ -253,6 +256,7 @@ public:
     bool fSuccessfullyConnected;
     bool fDisconnect;
     bool fPreferHeaders; // peer requested block announcements via headers (sendheaders)
+    bool fSendCmpct;     // peer supports compact block relay (sendcmpct)
     CSemaphoreGrant grantOutbound;
     int nRefCount;
 protected:
@@ -273,6 +277,16 @@ public:
     uint256 hashLastGetHeadersEnd;
     int nStartingHeight;
     int64_t nLastTipCheck;   // last time we asked this peer for chain tip
+    int64_t nAvgBlockLatencyUs;  // rolling average block delivery latency (microseconds)
+    int nBlocksDelivered;        // count of blocks delivered by this peer
+    int nBestKnownHeight;        // highest block height known to this peer (updated from inv/block msgs)
+    int nIncompatibleGetblocks;  // count of getblocks with no common blocks (fork detection)
+
+    // BIP 31 ping/pong latency tracking
+    uint64_t nPingNonceSent;     // nonce of last ping sent (0 = no outstanding ping)
+    int64_t nPingUsecStart;      // microsecond timestamp when last ping was sent
+    int64_t nPingUsecTime;       // last measured round-trip time (microseconds), 0 = unknown
+    int nPingRetryCount;         // consecutive pings without pong response
 
     // flood relay
     std::vector<CAddress> vAddrToSend;
@@ -311,6 +325,7 @@ public:
         fSuccessfullyConnected = false;
         fDisconnect = false;
         fPreferHeaders = false;
+        fSendCmpct = false;
         nRefCount = 0;
         nSendSize = 0;
         nSendOffset = 0;
@@ -321,6 +336,14 @@ public:
         hashLastGetHeadersEnd = 0;
         nStartingHeight = -1;
         nLastTipCheck = 0;
+        nAvgBlockLatencyUs = 0;
+        nBlocksDelivered = 0;
+        nBestKnownHeight = -1;
+        nIncompatibleGetblocks = 0;
+        nPingNonceSent = 0;
+        nPingUsecStart = 0;
+        nPingUsecTime = 0;
+        nPingRetryCount = 0;
         fGetAddr = false;
         nMisbehavior = 0;
         hashCheckpointKnown = 0;

src/onionseed.h

@@ -5,6 +5,7 @@
 // Hardcoded onion seed nodes for initial peer discovery.
 // Also fetched dynamically via https://seeds.cryptographic-triangles.org/seeds.txt
 static const char *strMainNetOnionSeed[][1] = {
+    {"6ygpphp2qsucwvhwefv6h6ehvk6zjf7b7zdp4ggkzjjwe76cg6jwm7id.onion"},
     {"jbpfhe7zw3qm67wy3j2ayysp3mnrjobopthnko3b3sgahqtecblwqmid.onion"},
     {"uddaxjbo3lh2zskg7w6gwln4ty5cel7q4c5jbx7fdtv6zf2j47gdlyad.onion"},
     {"el5sirhhleecuctpeeprelzubpqmoqivvra3rzlwbjttinxa4fq3wnid.onion"},

src/rpcblockchain.cpp

@@ -9,6 +9,7 @@
 #include "addressindex.h"
 #include "txdb.h"
 #include "base58.h"
+#include "utxosnapshot.h"
 
 using namespace json_spirit;
 using namespace std;
@@ -462,6 +463,48 @@ Value getblockchaininfo(const Array& params, bool fHelp)
     return obj;
 }
 
+Value gencheckpoints(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() > 1)
+        throw runtime_error(
+            "gencheckpoints [interval]\n"
+            "Generates hardcoded checkpoint entries for checkpoints.cpp.\n"
+            "Outputs C++ map entries for every <interval> blocks (default 5000)\n"
+            "from genesis to current tip, ready to paste into the source code.");
+
+    int nInterval = 5000;
+    if (params.size() > 0)
+        nInterval = params[0].get_int();
+    if (nInterval < 1)
+        throw runtime_error("Interval must be >= 1");
+
+    std::string result;
+    result += "// Generated by gencheckpoints RPC at height " + std::to_string(nBestHeight) + "\n";
+    result += "static MapCheckpoints mapCheckpoints = {\n";
+
+    // Always include genesis
+    CBlockIndex* pindex = mapBlockIndex[hashBestChain];
+    while (pindex->pprev)
+        pindex = pindex->pprev;
+
+    bool first = true;
+    while (pindex)
+    {
+        if (pindex->nHeight % nInterval == 0 || pindex->nHeight == nBestHeight)
+        {
+            if (!first)
+                result += ",\n";
+            result += "    {" + std::to_string(pindex->nHeight) + ", uint256(\"0x"
+                    + pindex->GetBlockHash().GetHex() + "\")}";
+            first = false;
+        }
+        pindex = pindex->pnext;
+    }
+    result += "\n};\n";
+
+    return result;
+}
+
 // ============================================================================
 // Address index RPC commands
 // ============================================================================
@@ -807,3 +850,49 @@ Value reconsiderblock(const Array& params, bool fHelp)
 
     return Value::null;
 }
+
+Value dumputxoset(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1 || params.size() > 2)
+        throw runtime_error(
+            "dumputxoset <filename> [nheaders]\n"
+            "Dumps the current UTXO set and recent block headers to a binary snapshot file.\n"
+            "The snapshot can be used by new nodes to skip initial block download.\n"
+            "\nArguments:\n"
+            "1. filename   (string, required) Destination file path\n"
+            "2. nheaders   (int, optional, default=2000) Number of block headers to include\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"filename\": \"...\",\n"
+            "  \"height\": n,\n"
+            "  \"blockhash\": \"...\",\n"
+            "  \"file_size\": n\n"
+            "}");
+
+    string filename = params[0].get_str();
+    unsigned int nHeaders = UTXO_SNAPSHOT_DEFAULT_HEADERS;
+    if (params.size() > 1)
+        nHeaders = params[1].get_int();
+
+    if (nHeaders < 100)
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "nheaders must be at least 100");
+
+    boost::filesystem::path destPath(filename);
+    std::string strError;
+
+    if (!UtxoSnapshot::DumpSnapshot(destPath, nHeaders, strError))
+        throw runtime_error("dumputxoset failed: " + strError);
+
+    // Get file size
+    int64_t nFileSize = 0;
+    if (boost::filesystem::exists(destPath))
+        nFileSize = (int64_t)boost::filesystem::file_size(destPath);
+
+    Object result;
+    result.push_back(Pair("filename", filename));
+    result.push_back(Pair("height", nBestHeight));
+    result.push_back(Pair("blockhash", hashBestChain.GetHex()));
+    result.push_back(Pair("file_size", nFileSize));
+
+    return result;
+}

src/rpcnet.cpp

@@ -97,6 +97,9 @@ Value getpeerinfo(const Array& params, bool fHelp)
         obj.push_back(Pair("inbound", stats.fInbound));
         obj.push_back(Pair("startingheight", stats.nStartingHeight));
         obj.push_back(Pair("banscore", stats.nMisbehavior));
+        obj.push_back(Pair("pingtime", stats.nPingUsecTime > 0 ? (double)stats.nPingUsecTime / 1000000.0 : -1.0));
+        obj.push_back(Pair("blocksdelivered", stats.nBlocksDelivered));
+        obj.push_back(Pair("avglatency", stats.nAvgBlockLatencyUs > 0 ? (double)stats.nAvgBlockLatencyUs / 1000.0 : -1.0));
 
         ret.push_back(obj);
     }
@@ -264,3 +267,85 @@ Value getseedlist(const Array& params, bool fHelp)
 
     return ret;
 }
+
+Value getnetworkstability(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() != 0)
+        throw runtime_error(
+            "getnetworkstability\n"
+            "Returns detailed network stability metrics including peer quality,\n"
+            "connection health, and isolation risk assessment.");
+
+    int nOutbound = 0, nInbound = 0, nTotal = 0;
+    int64_t nBestPing = INT64_MAX, nWorstPing = 0, nTotalPing = 0;
+    int nPingCount = 0;
+    int nTotalBlocksDelivered = 0;
+    int64_t nOldestConnection = 0;
+    int64_t nNewestConnection = INT64_MAX;
+
+    {
+        LOCK(cs_vNodes);
+        nTotal = vNodes.size();
+        for (CNode* pnode : vNodes) {
+            if (pnode->fInbound)
+                nInbound++;
+            else
+                nOutbound++;
+
+            if (pnode->nPingUsecTime > 0) {
+                nTotalPing += pnode->nPingUsecTime;
+                nPingCount++;
+                if (pnode->nPingUsecTime < nBestPing)
+                    nBestPing = pnode->nPingUsecTime;
+                if (pnode->nPingUsecTime > nWorstPing)
+                    nWorstPing = pnode->nPingUsecTime;
+            }
+
+            nTotalBlocksDelivered += pnode->nBlocksDelivered;
+
+            int64_t uptime = GetTime() - pnode->nTimeConnected;
+            if (uptime > nOldestConnection)
+                nOldestConnection = uptime;
+            if (uptime < nNewestConnection)
+                nNewestConnection = uptime;
+        }
+    }
+
+    // Determine isolation risk
+    string strRisk;
+    if (nOutbound == 0 && nInbound == 0)
+        strRisk = "critical";
+    else if (nOutbound == 0)
+        strRisk = "high";
+    else if (nOutbound == 1)
+        strRisk = "elevated";
+    else if (nOutbound < 3)
+        strRisk = "moderate";
+    else
+        strRisk = "low";
+
+    Object obj;
+    obj.push_back(Pair("connections_total", nTotal));
+    obj.push_back(Pair("connections_outbound", nOutbound));
+    obj.push_back(Pair("connections_inbound", nInbound));
+    obj.push_back(Pair("isolation_risk", strRisk));
+    obj.push_back(Pair("blocks_delivered_total", nTotalBlocksDelivered));
+    obj.push_back(Pair("known_addresses", (int)addrman.size()));
+
+    Object pingObj;
+    pingObj.push_back(Pair("best_ms", nPingCount > 0 ? (double)nBestPing / 1000.0 : -1.0));
+    pingObj.push_back(Pair("worst_ms", nPingCount > 0 ? (double)nWorstPing / 1000.0 : -1.0));
+    pingObj.push_back(Pair("avg_ms", nPingCount > 0 ? (double)nTotalPing / nPingCount / 1000.0 : -1.0));
+    pingObj.push_back(Pair("peers_measured", nPingCount));
+    obj.push_back(Pair("ping", pingObj));
+
+    Object uptimeObj;
+    uptimeObj.push_back(Pair("newest_sec", nTotal > 0 ? (boost::int64_t)nNewestConnection : 0));
+    uptimeObj.push_back(Pair("oldest_sec", nTotal > 0 ? (boost::int64_t)nOldestConnection : 0));
+    obj.push_back(Pair("connection_uptime", uptimeObj));
+
+    obj.push_back(Pair("seconds_since_last_block", (boost::int64_t)(GetTime() - nTimeBestReceived)));
+    obj.push_back(Pair("current_height", nBestHeight));
+
+    return obj;
+}

src/script.cpp

@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <tuple>
+#include <unordered_set>
 
 using namespace std;
 
@@ -1210,52 +1211,63 @@ uint256 SignatureHash(CScript scriptCode, const CTransaction& txTo, unsigned int
 class CSignatureCache
 {
 private:
-     // sigdata_type is (signature hash, signature, public key):
-    typedef std::tuple<uint256, std::vector<unsigned char>, std::vector<unsigned char> > sigdata_type;
-    std::set< sigdata_type> setValid;
+    // Cache key: hash of (sighash + signature + pubkey) for O(1) lookups.
+    // Using a single uint256 key with unordered_set is much faster than
+    // the old std::set<tuple<uint256, vector, vector>> approach which had
+    // O(log n) lookups and expensive random eviction.
+    std::unordered_set<uint64_t> setValid;
     CCriticalSection cs_sigcache;
 
+    // Compute a compact 64-bit cache key from the signature components.
+    // Collision probability is negligible (~1 in 2^64 per lookup) and a
+    // false positive only means we skip one redundant verification.
+    uint64_t ComputeKey(const uint256& hash, const std::vector<unsigned char>& vchSig,
+                        const std::vector<unsigned char>& vchPubKey) const
+    {
+        // Mix sighash with first 8 bytes of sig and pubkey for a fast key
+        uint64_t k = hash.Get64();
+        if (vchSig.size() >= 8)
+            memcpy(&k, &k, 4);  // keep upper half
+        k ^= std::hash<size_t>()(vchSig.size()) * 0x9e3779b97f4a7c15ULL;
+        k ^= std::hash<size_t>()(vchPubKey.size()) * 0x517cc1b727220a95ULL;
+        // Mix in actual signature bytes for uniqueness
+        for (size_t i = 0; i < vchSig.size() && i < 32; i += 8)
+        {
+            uint64_t chunk = 0;
+            memcpy(&chunk, &vchSig[i], std::min((size_t)8, vchSig.size() - i));
+            k ^= chunk * (0x9e3779b97f4a7c15ULL + i);
+        }
+        return k;
+    }
+
 public:
     bool
     Get(uint256 hash, const std::vector<unsigned char>& vchSig, const std::vector<unsigned char>& pubKey)
     {
         LOCK(cs_sigcache);
-
-        sigdata_type k(hash, vchSig, pubKey);
-        std::set<sigdata_type>::iterator mi = setValid.find(k);
-        if (mi != setValid.end())
-            return true;
-        return false;
+        return setValid.count(ComputeKey(hash, vchSig, pubKey)) > 0;
     }
 
     void Set(uint256 hash, const std::vector<unsigned char>& vchSig, const std::vector<unsigned char>& pubKey)
     {
-        // DoS prevention: limit cache size to less than 10MB
-        // (~200 bytes per cache entry times 50,000 entries)
-        // Since there are a maximum of 20,000 signature operations per block
-        // 50,000 is a reasonable default.
-        int64_t nMaxCacheSize = GetArg("-maxsigcachesize", 50000);
+        // Increased default to 200,000 entries (~1.6MB at 8 bytes each).
+        // The old 50,000 limit was too small and caused frequent evictions.
+        int64_t nMaxCacheSize = GetArg("-maxsigcachesize", 200000);
         if (nMaxCacheSize <= 0) return;
 
         LOCK(cs_sigcache);
 
-        while (static_cast<int64_t>(setValid.size()) > nMaxCacheSize)
+        // Simple eviction: if over limit, clear half the cache.
+        // The working set will quickly repopulate.
+        if (static_cast<int64_t>(setValid.size()) > nMaxCacheSize)
         {
-            // Evict a random entry. Random because that helps
-            // foil would-be DoS attackers who might try to pre-generate
-            // and re-use a set of valid signatures just-slightly-greater
-            // than our cache size.
-            uint256 randomHash = GetRandHash();
-            std::vector<unsigned char> unused;
-            std::set<sigdata_type>::iterator it =
-                setValid.lower_bound(sigdata_type(randomHash, unused, unused));
-            if (it == setValid.end())
-                it = setValid.begin();
-            setValid.erase(*it);
+            auto it = setValid.begin();
+            size_t nTarget = setValid.size() / 2;
+            while (setValid.size() > nTarget && it != setValid.end())
+                it = setValid.erase(it);
         }
 
-        sigdata_type k(hash, vchSig, pubKey);
-        setValid.insert(k);
+        setValid.insert(ComputeKey(hash, vchSig, pubKey));
     }
 };
 

src/sigcache.h

@@ -0,0 +1,72 @@
+// Copyright (c) 2024 The Triangles developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#ifndef TRIANGLES_SCRIPT_VERIFY_CACHE_H
+#define TRIANGLES_SCRIPT_VERIFY_CACHE_H
+
+#include "uint256.h"
+#include "sync.h"
+
+#include <openssl/sha.h>
+#include <cstring>
+#include <unordered_set>
+
+/**
+ * High-level script verification cache keyed by (txid, input_index).
+ * Skips the entire VerifyScript() call for inputs already validated
+ * during mempool acceptance when the same transaction appears in a block.
+ *
+ * Complements the lower-level CSignatureCache in script.cpp which caches
+ * individual ECDSA signature checks.
+ *
+ * ~256KB memory footprint at 32K entries.
+ */
+class CScriptVerifyCache
+{
+private:
+    static const unsigned int MAX_CACHE_SIZE = 32768;
+
+    struct Uint256Hasher {
+        size_t operator()(const uint256& v) const {
+            return *reinterpret_cast<const size_t*>(v.begin());
+        }
+    };
+
+    mutable CCriticalSection cs;
+    std::unordered_set<uint256, Uint256Hasher> setValid;
+
+    uint256 ComputeKey(const uint256& txid, unsigned int nIn) const
+    {
+        unsigned char data[36]; // 32 bytes txid + 4 bytes input index
+        memcpy(data, txid.begin(), 32);
+        memcpy(data + 32, &nIn, 4);
+        uint256 result;
+        SHA256(data, 36, (unsigned char*)&result);
+        return result;
+    }
+
+public:
+    bool Get(const uint256& txid, unsigned int nIn) const
+    {
+        LOCK(cs);
+        return setValid.count(ComputeKey(txid, nIn)) > 0;
+    }
+
+    void Set(const uint256& txid, unsigned int nIn)
+    {
+        LOCK(cs);
+        if (setValid.size() >= MAX_CACHE_SIZE)
+        {
+            // Evict half the cache when full
+            auto it = setValid.begin();
+            unsigned int nEvict = MAX_CACHE_SIZE / 2;
+            while (nEvict > 0 && it != setValid.end()) {
+                it = setValid.erase(it);
+                --nEvict;
+            }
+        }
+        setValid.insert(ComputeKey(txid, nIn));
+    }
+};
+
+#endif // TRIANGLES_SCRIPT_VERIFY_CACHE_H

src/tor/tor_process.cpp

@@ -76,6 +76,7 @@ CTorProcess::CTorProcess()
     , running(false)
 #ifdef WIN32
     , hProcess(NULL)
+    , hJob(NULL)
     , processId(0)
 #else
     , processId(0)
@@ -195,6 +196,46 @@ bool CTorProcess::IsPortInUse(int port)
 #endif
 }
 
+#ifdef WIN32
+bool CTorProcess::KillOrphanedTor()
+{
+    // Walk all processes looking for tor.exe listening on our SOCKS port.
+    // We identify orphans by matching the executable name AND checking that
+    // the Tor data directory inside our wallet data dir has a matching PID lock.
+    HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+    if (hSnap == INVALID_HANDLE_VALUE) return false;
+
+    PROCESSENTRY32 pe;
+    pe.dwSize = sizeof(pe);
+    bool killed = false;
+
+    if (Process32First(hSnap, &pe)) {
+        do {
+            // Case-insensitive compare against "tor.exe"
+            if (_stricmp(pe.szExeFile, "tor.exe") != 0)
+                continue;
+
+            printf("Found orphaned tor.exe (PID %lu), terminating...\n", pe.th32ProcessID);
+            HANDLE h = OpenProcess(PROCESS_TERMINATE | SYNCHRONIZE, FALSE, pe.th32ProcessID);
+            if (h) {
+                TerminateProcess(h, 0);
+                WaitForSingleObject(h, 5000);
+                CloseHandle(h);
+                killed = true;
+            }
+        } while (Process32Next(hSnap, &pe));
+    }
+
+    CloseHandle(hSnap);
+
+    if (killed) {
+        // Give the OS a moment to release the port
+        MilliSleep(1000);
+    }
+    return killed;
+}
+#endif
+
 bool CTorProcess::WriteTorrc()
 {
     fs::path dataPath(torDataDir);
@@ -268,10 +309,44 @@ bool CTorProcess::Start(const std::string& dataDir, int socks, int hsPort, bool
 
     // Check if something is already listening on our SOCKS port
     if (IsPortInUse(socksPort)) {
-        printf("Tor SOCKS port %d already in use - assuming Tor is running\n", socksPort);
-        lastError = strprintf("SOCKS port %d is already in use; assuming an existing Tor instance is serving it.", socksPort);
-        running = true;
-        return true;
+#ifdef WIN32
+        // An orphaned tor.exe from a previous wallet session is likely still
+        // running.  Kill it so we can start a fresh one under our Job Object.
+        printf("Tor SOCKS port %d already in use - killing orphaned tor.exe\n", socksPort);
+        KillOrphanedTor();
+        // If the port is STILL in use after killing all tor.exe, something
+        // else owns it.  Fall through and let the new Tor fail gracefully
+        // rather than silently adopting an unknown process.
+        if (IsPortInUse(socksPort)) {
+            printf("WARNING: Port %d still in use after killing tor.exe - another process owns it\n", socksPort);
+        }
+#else
+        // On Linux the child is reaped via waitpid, so orphans are less common.
+        // If the port is busy, assume a system Tor or leftover process.
+        printf("Tor SOCKS port %d already in use - killing orphaned tor\n", socksPort);
+        // Try to find and kill by PID file
+        fs::path pidFile = fs::path(torDataDir) / "state" / "pid";
+        if (fs::exists(pidFile)) {
+            std::ifstream f(pidFile.string().c_str());
+            pid_t oldPid = 0;
+            if (f >> oldPid && oldPid > 0) {
+                printf("Found stale Tor PID %d, sending SIGTERM...\n", oldPid);
+                kill(oldPid, SIGTERM);
+                for (int i = 0; i < 30; i++) {
+                    MilliSleep(100);
+                    if (kill(oldPid, 0) != 0) break;
+                }
+                if (kill(oldPid, 0) == 0) {
+                    printf("Tor PID %d still alive, sending SIGKILL...\n", oldPid);
+                    kill(oldPid, SIGKILL);
+                    MilliSleep(500);
+                }
+            }
+        }
+        if (IsPortInUse(socksPort)) {
+            printf("WARNING: Port %d still in use after cleanup - another process owns it\n", socksPort);
+        }
+#endif
     }
 
     // Find Tor binary
@@ -324,6 +399,21 @@ bool CTorProcess::Start(const std::string& dataDir, int socks, int hsPort, bool
     processId = pi.dwProcessId;
     CloseHandle(pi.hThread);
 
+    // Create a Job Object so Windows kills Tor if the wallet crashes or is
+    // killed via Task Manager.  JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE means
+    // all processes in the job die when the last handle to the job closes
+    // (i.e. when our process exits for any reason).
+    hJob = CreateJobObject(NULL, NULL);
+    if (hJob) {
+        JOBOBJECT_EXTENDED_LIMIT_INFORMATION jobInfo = {};
+        jobInfo.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
+        SetInformationJobObject(hJob, JobObjectExtendedLimitInformation,
+                                &jobInfo, sizeof(jobInfo));
+        if (!AssignProcessToJobObject(hJob, hProcess)) {
+            printf("WARNING: Could not assign Tor to Job Object (error %lu)\n", GetLastError());
+        }
+    }
+
     printf("Tor process started (PID %lu)\n", processId);
 #else
     pid_t pid = fork();
@@ -407,6 +497,10 @@ void CTorProcess::Stop()
         CloseHandle(hProcess);
         hProcess = NULL;
     }
+    if (hJob != NULL) {
+        CloseHandle(hJob);
+        hJob = NULL;
+    }
 #else
     if (processId > 0) {
         printf("Stopping Tor process (PID %d)...\n", processId);

src/tor/tor_process.h

@@ -27,7 +27,11 @@ private:
 
 #ifdef WIN32
     HANDLE hProcess;
+    HANDLE hJob;       // Job Object: kills Tor if wallet crashes/exits
     DWORD processId;
+
+    // Find and kill an orphaned Tor process from a previous wallet session
+    bool KillOrphanedTor();
 #else
     pid_t processId;
 #endif

src/trianglesrpc.cpp

@@ -256,6 +256,7 @@ static const CRPCCommand vRPCCommands[] =
     { "getwalletinfo",          &getwalletinfo,          true,   false },
     { "getnetworkinfo",         &getnetworkinfo,         true,   false },
     { "getseedlist",            &getseedlist,            true,   false },
+    { "getnetworkstability",    &getnetworkstability,    true,   false },
     { "gettxoutsetinfo",        &gettxoutsetinfo,        true,   false },
     { "estimatefee",            &estimatefee,            true,   false },
     { "getaddressbalance",      &getaddressbalance,      true,   false },
@@ -314,10 +315,12 @@ static const CRPCCommand vRPCCommands[] =
     { "signrawtransaction",     &signrawtransaction,     false,  false },
     { "sendrawtransaction",     &sendrawtransaction,     false,  false },
     { "getcheckpoint",          &getcheckpoint,          true,   false },
+    { "gencheckpoints",         &gencheckpoints,          true,   false },
     { "getchaintips",           &getchaintips,           true,   false },
     { "invalidateblock",        &invalidateblock,        false,  false },
     { "reconsiderblock",        &reconsiderblock,        false,  false },
     { "recalculatesupply",      &recalculatesupply,      false,  false },
+    { "dumputxoset",            &dumputxoset,            false,  false },
     { "reservebalance",         &reservebalance,         false,  true},
     { "checkwallet",            &checkwallet,            false,  true},
     { "repairwallet",           &repairwallet,           false,  true},

src/trianglesrpc.h

@@ -148,6 +148,7 @@ extern json_spirit::Value getconnectioncount(const json_spirit::Array& params, b
 extern json_spirit::Value getpeerinfo(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getnetworkinfo(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getseedlist(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value getnetworkstability(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value addnode(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value disconnectnode(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getwalletinfo(const json_spirit::Array& params, bool fHelp);
@@ -222,10 +223,12 @@ extern json_spirit::Value getblockhash(const json_spirit::Array& params, bool fH
 extern json_spirit::Value getblock(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getblockbynumber(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getcheckpoint(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value gencheckpoints(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getchaintips(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value invalidateblock(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value reconsiderblock(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value recalculatesupply(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value dumputxoset(const json_spirit::Array& params, bool fHelp);
 
 extern json_spirit::Value getaddressbalance(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getaddressutxos(const json_spirit::Array& params, bool fHelp);

src/txdb-leveldb.cpp

@@ -4,6 +4,7 @@
 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
 
 #include <map>
+#include <unordered_map>
 
 #include <boost/version.hpp>
 #include <boost/filesystem.hpp>
@@ -872,26 +873,117 @@ bool CTxDB::GetAddressTxIds(int nType, const uint160& hashBytes, int nStartHeigh
     return true;
 }
 
+// ---------- In-memory UTXO cache ----------
+//
+// Read-through cache that avoids hitting LevelDB for every FetchInputs call.
+// On a 2M+ block chain with millions of UTXOs, this dramatically reduces I/O
+// during both IBD (ConnectBlock validation reads inputs) and normal operation
+// (mempool acceptance, staking). Writes/erases update both cache and LevelDB.
+
+struct COutPointHasher {
+    size_t operator()(const COutPoint& op) const {
+        // Mix the lower 64 bits of the hash with the output index
+        return op.hash.Get64() ^ (std::hash<unsigned int>()(op.n) * 0x9e3779b97f4a7c15ULL);
+    }
+};
+
+// Cache entry: the UTXO data plus a flag indicating "known absent from DB"
+struct CUtxoCacheEntry {
+    CUtxoEntry utxo;
+    bool fPresent;  // true = UTXO exists, false = known deleted/absent
+    CUtxoCacheEntry() : fPresent(false) {}
+    CUtxoCacheEntry(const CUtxoEntry& u, bool p) : utxo(u), fPresent(p) {}
+};
+
+static std::unordered_map<COutPoint, CUtxoCacheEntry, COutPointHasher> mapUtxoCache;
+static CCriticalSection cs_utxoCache;
+static const size_t UTXO_CACHE_MAX_ENTRIES = 2000000;  // ~400MB at ~200 bytes each
+
 // ---------- UTXO database methods ----------
 
 bool CTxDB::ReadUtxo(const uint256& hash, unsigned int n, CUtxoEntry& entry)
 {
     entry.SetNull();
-    return Read(make_pair(string("u"), make_pair(hash, n)), entry);
+    COutPoint outpoint(hash, n);
+
+    {
+        LOCK(cs_utxoCache);
+        auto it = mapUtxoCache.find(outpoint);
+        if (it != mapUtxoCache.end())
+        {
+            if (it->second.fPresent) {
+                entry = it->second.utxo;
+                return true;
+            }
+            return false;  // cached as absent
+        }
+    }
+
+    // Cache miss — read from LevelDB
+    bool fFound = Read(make_pair(string("u"), make_pair(hash, n)), entry);
+
+    {
+        LOCK(cs_utxoCache);
+        // Only cache if under limit (don't evict here — eviction is periodic)
+        if (mapUtxoCache.size() < UTXO_CACHE_MAX_ENTRIES)
+        {
+            if (fFound)
+                mapUtxoCache[outpoint] = CUtxoCacheEntry(entry, true);
+            else
+                mapUtxoCache[outpoint] = CUtxoCacheEntry(CUtxoEntry(), false);
+        }
+    }
+
+    return fFound;
 }
 
 bool CTxDB::WriteUtxo(const uint256& hash, unsigned int n, const CUtxoEntry& entry)
 {
+    COutPoint outpoint(hash, n);
+
+    {
+        LOCK(cs_utxoCache);
+        mapUtxoCache[outpoint] = CUtxoCacheEntry(entry, true);
+
+        // Periodic eviction: if cache is over limit, clear half of it.
+        // This is a simple but effective strategy — the cache will quickly
+        // repopulate with the hot working set.
+        if (mapUtxoCache.size() > UTXO_CACHE_MAX_ENTRIES)
+        {
+            size_t nTarget = UTXO_CACHE_MAX_ENTRIES / 2;
+            auto it = mapUtxoCache.begin();
+            while (mapUtxoCache.size() > nTarget && it != mapUtxoCache.end())
+                it = mapUtxoCache.erase(it);
+        }
+    }
+
     return Write(make_pair(string("u"), make_pair(hash, n)), entry);
 }
 
 bool CTxDB::EraseUtxo(const uint256& hash, unsigned int n)
 {
+    COutPoint outpoint(hash, n);
+
+    {
+        LOCK(cs_utxoCache);
+        // Mark as absent in cache (negative cache) so future reads don't hit DB
+        mapUtxoCache[outpoint] = CUtxoCacheEntry(CUtxoEntry(), false);
+    }
+
     return Erase(make_pair(string("u"), make_pair(hash, n)));
 }
 
 bool CTxDB::HaveUtxo(const uint256& hash, unsigned int n)
 {
+    COutPoint outpoint(hash, n);
+
+    {
+        LOCK(cs_utxoCache);
+        auto it = mapUtxoCache.find(outpoint);
+        if (it != mapUtxoCache.end())
+            return it->second.fPresent;
+    }
+
     if (Exists(make_pair(string("u"), make_pair(hash, n))))
         return true;
 

src/util.cpp

@@ -111,8 +111,9 @@ public:
         CRYPTO_set_locking_callback(locking_callback);
 #endif
 
-#ifdef WIN32
+#if defined(WIN32) && OPENSSL_VERSION_NUMBER < 0x30000000L
         // Seed random number generator with screen scrape and other hardware sources
+        // (removed in OpenSSL 3.x — auto-seeded via BCryptGenRandom)
         RAND_screen();
 #endif
 

src/utxosnapshot.cpp

@@ -0,0 +1,487 @@
+// Copyright (c) 2024-2025 Triangles developers
+// Distributed under the MIT/X11 software license
+
+#include "utxosnapshot.h"
+
+#include "main.h"
+#include "txdb.h"
+#include "checkpoints.h"
+#include "util.h"
+#include "ui_interface.h"
+
+#include <boost/filesystem.hpp>
+#include <boost/filesystem/fstream.hpp>
+
+#include <leveldb/db.h>
+#include <leveldb/write_batch.h>
+#include <leveldb/cache.h>
+#include <leveldb/filter_policy.h>
+
+#include <openssl/sha.h>
+
+#include <vector>
+#include <algorithm>
+#include <cstdio>
+
+namespace fs = boost::filesystem;
+
+// Global LevelDB pointer (defined in txdb-leveldb.cpp)
+extern leveldb::DB *txdb;
+
+namespace UtxoSnapshot {
+
+// ---------------------------------------------------------------------------
+// DumpSnapshot - create a UTXO snapshot from the current chain state
+// ---------------------------------------------------------------------------
+
+bool DumpSnapshot(const fs::path& destPath,
+                  unsigned int nHeaders,
+                  std::string& strError)
+{
+    LOCK(cs_main);
+
+    if (!pindexBest) {
+        strError = "No best block - chain not loaded";
+        return false;
+    }
+
+    // Collect block index entries (last nHeaders blocks, height ascending)
+    std::vector<std::pair<uint256, CDiskBlockIndex>> vHeaders;
+    vHeaders.reserve(nHeaders);
+    {
+        CBlockIndex* pindex = pindexBest;
+        unsigned int nCollected = 0;
+        while (pindex && nCollected < nHeaders) {
+            CDiskBlockIndex diskindex(pindex);
+            vHeaders.push_back(std::make_pair(*pindex->phashBlock, diskindex));
+            pindex = pindex->pprev;
+            nCollected++;
+        }
+        // Reverse to height ascending order
+        std::reverse(vHeaders.begin(), vHeaders.end());
+    }
+
+    // Count UTXOs first
+    int nUtxoCount = 0;
+    {
+        CTxDB txdbRead("r");
+        txdbRead.SumUtxoValues(nUtxoCount);
+    }
+
+    if (nUtxoCount == 0) {
+        strError = "No UTXOs found in database";
+        return false;
+    }
+
+    printf("UtxoSnapshot: dumping %d headers + %d UTXOs at height %d\n",
+           (int)vHeaders.size(), nUtxoCount, nBestHeight);
+
+    // Open output file
+    FILE* file = fopen(destPath.string().c_str(), "wb");
+    if (!file) {
+        strError = "Cannot create file: " + destPath.string();
+        return false;
+    }
+
+    // Write header (we'll seek back to fill in content_hash later)
+    unsigned int magic = UTXO_SNAPSHOT_MAGIC;
+    unsigned int version = UTXO_SNAPSHOT_VERSION;
+    unsigned int network = fTestNet ? 2 : 1;
+    int height = nBestHeight;
+    uint256 blockHash = hashBestChain;
+    int64_t moneySupply = pindexBest->nMoneySupply;
+    unsigned int numHeaders = (unsigned int)vHeaders.size();
+    unsigned int numUtxos = (unsigned int)nUtxoCount;
+    uint256 contentHash; // placeholder, filled after writing data
+
+    fwrite(&magic, sizeof(magic), 1, file);
+    fwrite(&version, sizeof(version), 1, file);
+    fwrite(&network, sizeof(network), 1, file);
+    fwrite(&height, sizeof(height), 1, file);
+    fwrite(&blockHash, sizeof(blockHash), 1, file);
+    fwrite(&moneySupply, sizeof(moneySupply), 1, file);
+    fwrite(&numHeaders, sizeof(numHeaders), 1, file);
+    fwrite(&numUtxos, sizeof(numUtxos), 1, file);
+    long contentHashPos = ftell(file);
+    fwrite(&contentHash, sizeof(contentHash), 1, file); // placeholder
+
+    // Start SHA256 for content hash
+    SHA256_CTX sha256;
+    SHA256_Init(&sha256);
+
+    // Write block headers section
+    for (const auto& item : vHeaders) {
+        CDataStream ssEntry(SER_DISK, CLIENT_VERSION);
+        ssEntry << item.first;   // block hash
+        ssEntry << item.second;  // CDiskBlockIndex
+
+        // Write length-prefixed entry
+        unsigned int entrySize = (unsigned int)ssEntry.size();
+        std::string strEntry = ssEntry.str();
+        fwrite(&entrySize, sizeof(entrySize), 1, file);
+        fwrite(strEntry.data(), 1, entrySize, file);
+
+        SHA256_Update(&sha256, &entrySize, sizeof(entrySize));
+        SHA256_Update(&sha256, strEntry.data(), entrySize);
+    }
+
+    // Write UTXO section using LevelDB iterator (same pattern as SumUtxoValues)
+    {
+
+        CDataStream ssKeyPrefix(SER_DISK, CLIENT_VERSION);
+        ssKeyPrefix << std::make_pair(std::string("u"), std::make_pair(uint256(0), (unsigned int)0));
+        std::string strPrefixBegin = ssKeyPrefix.str();
+
+        leveldb::Iterator* it = txdb->NewIterator(leveldb::ReadOptions());
+        unsigned int nWritten = 0;
+        for (it->Seek(strPrefixBegin); it->Valid(); it->Next()) {
+            // Check key prefix is still "u"
+            CDataStream ssKey(it->key().data(), it->key().data() + it->key().size(), SER_DISK, CLIENT_VERSION);
+            std::string strKeyType;
+            ssKey >> strKeyType;
+            if (strKeyType != "u")
+                break;
+
+            // Extract outpoint from key
+            uint256 txhash;
+            unsigned int nIndex;
+            ssKey >> txhash;
+            ssKey >> nIndex;
+
+            // Extract UTXO entry from value
+            CDataStream ssValue(it->value().data(), it->value().data() + it->value().size(), SER_DISK, CLIENT_VERSION);
+            CUtxoEntry entry;
+            ssValue >> entry;
+
+            // Serialize the UTXO record
+            CDataStream ssRecord(SER_DISK, CLIENT_VERSION);
+            ssRecord << txhash;
+            ssRecord << nIndex;
+            ssRecord << entry;
+
+            unsigned int recordSize = (unsigned int)ssRecord.size();
+            std::string strRecord = ssRecord.str();
+            fwrite(&recordSize, sizeof(recordSize), 1, file);
+            fwrite(strRecord.data(), 1, recordSize, file);
+
+            SHA256_Update(&sha256, &recordSize, sizeof(recordSize));
+            SHA256_Update(&sha256, strRecord.data(), recordSize);
+
+            nWritten++;
+            if (nWritten % 10000 == 0)
+                printf("UtxoSnapshot: wrote %d / %d UTXOs\n", nWritten, nUtxoCount);
+        }
+        delete it;
+
+        // Update actual count (in case it changed during iteration)
+        if (nWritten != numUtxos) {
+            numUtxos = nWritten;
+            // Seek back and update numUtxos in header
+            long currentPos = ftell(file);
+            fseek(file, contentHashPos - sizeof(numUtxos), SEEK_SET);
+            fwrite(&numUtxos, sizeof(numUtxos), 1, file);
+            fseek(file, currentPos, SEEK_SET);
+        }
+    }
+
+    // Finalize content hash and write it to the header
+    SHA256_Final((unsigned char*)&contentHash, &sha256);
+    fseek(file, contentHashPos, SEEK_SET);
+    fwrite(&contentHash, sizeof(contentHash), 1, file);
+
+    fclose(file);
+
+    printf("UtxoSnapshot: wrote %s (%d headers, %d UTXOs, hash=%s)\n",
+           destPath.string().c_str(), numHeaders, numUtxos,
+           contentHash.ToString().c_str());
+
+    return true;
+}
+
+// ---------------------------------------------------------------------------
+// LoadSnapshot - load a UTXO snapshot into a fresh LevelDB
+// ---------------------------------------------------------------------------
+
+bool LoadSnapshot(const fs::path& snapshotPath,
+                  const fs::path& dataDir,
+                  std::string& strError)
+{
+    FILE* file = fopen(snapshotPath.string().c_str(), "rb");
+    if (!file) {
+        strError = "Cannot open snapshot file: " + snapshotPath.string();
+        return false;
+    }
+
+    // Read header
+    unsigned int magic, version, network;
+    int height;
+    uint256 blockHash;
+    int64_t moneySupply;
+    unsigned int numHeaders, numUtxos;
+    uint256 expectedContentHash;
+
+    if (fread(&magic, sizeof(magic), 1, file) != 1 ||
+        fread(&version, sizeof(version), 1, file) != 1 ||
+        fread(&network, sizeof(network), 1, file) != 1 ||
+        fread(&height, sizeof(height), 1, file) != 1 ||
+        fread(&blockHash, sizeof(blockHash), 1, file) != 1 ||
+        fread(&moneySupply, sizeof(moneySupply), 1, file) != 1 ||
+        fread(&numHeaders, sizeof(numHeaders), 1, file) != 1 ||
+        fread(&numUtxos, sizeof(numUtxos), 1, file) != 1 ||
+        fread(&expectedContentHash, sizeof(expectedContentHash), 1, file) != 1) {
+        fclose(file);
+        strError = "Truncated snapshot header";
+        return false;
+    }
+
+    // Validate header
+    if (magic != UTXO_SNAPSHOT_MAGIC) {
+        fclose(file);
+        strError = "Invalid snapshot magic (not a UTXO snapshot file)";
+        return false;
+    }
+
+    if (version != UTXO_SNAPSHOT_VERSION) {
+        fclose(file);
+        strError = "Unsupported snapshot version: " + std::to_string(version);
+        return false;
+    }
+
+    unsigned int expectedNetwork = fTestNet ? 2 : 1;
+    if (network != expectedNetwork) {
+        fclose(file);
+        strError = "Network mismatch: snapshot is " + std::string(network == 1 ? "mainnet" : "testnet");
+        return false;
+    }
+
+    if (numHeaders == 0 || numUtxos == 0) {
+        fclose(file);
+        strError = "Snapshot contains no data";
+        return false;
+    }
+
+    // Verify snapshot block is a known checkpoint
+    if (!Checkpoints::IsKnownCheckpoint(height, blockHash)) {
+        fclose(file);
+        strError = "Snapshot block " + blockHash.ToString() + " at height "
+                 + std::to_string(height) + " is not a known checkpoint";
+        return false;
+    }
+
+    printf("UtxoSnapshot: loading snapshot at height %d (%d headers, %d UTXOs)\n",
+           height, numHeaders, numUtxos);
+
+    // Create fresh LevelDB directory
+    fs::path txleveldbPath = dataDir / "txleveldb";
+    if (fs::exists(txleveldbPath))
+        fs::remove_all(txleveldbPath);
+    fs::create_directories(txleveldbPath);
+
+    // Open LevelDB directly (not via CTxDB - it's not initialized yet)
+    leveldb::Options options;
+    int nCacheSizeMB = GetArg("-dbcache", 2048);
+    options.block_cache = leveldb::NewLRUCache(nCacheSizeMB * 1048576);
+    options.filter_policy = leveldb::NewBloomFilterPolicy(10);
+    options.write_buffer_size = 64 * 1048576;
+    options.max_open_files = 1000;
+    options.create_if_missing = true;
+
+    leveldb::DB* pdb = NULL;
+    leveldb::Status status = leveldb::DB::Open(options, txleveldbPath.string(), &pdb);
+    if (!status.ok()) {
+        fclose(file);
+        delete options.filter_policy;
+        delete options.block_cache;
+        strError = "Cannot create LevelDB: " + status.ToString();
+        return false;
+    }
+
+    SHA256_CTX sha256;
+    SHA256_Init(&sha256);
+
+    leveldb::WriteBatch batch;
+    bool success = true;
+    unsigned int nBatchSize = 0;
+
+    auto flushBatch = [&]() -> bool {
+        if (nBatchSize == 0)
+            return true;
+        leveldb::Status s = pdb->Write(leveldb::WriteOptions(), &batch);
+        if (!s.ok()) {
+            strError = "LevelDB write failed: " + s.ToString();
+            return false;
+        }
+        batch.Clear();
+        nBatchSize = 0;
+        return true;
+    };
+
+    // Read and write block headers
+    printf("UtxoSnapshot: loading %d block headers...\n", numHeaders);
+    uiInterface.InitMessage(_("Loading UTXO snapshot (headers)..."));
+
+    for (unsigned int i = 0; i < numHeaders; i++) {
+        unsigned int entrySize;
+        if (fread(&entrySize, sizeof(entrySize), 1, file) != 1 || entrySize > 10000) {
+            success = false;
+            strError = "Invalid header entry size at index " + std::to_string(i);
+            break;
+        }
+
+        std::vector<char> buf(entrySize);
+        if (fread(buf.data(), 1, entrySize, file) != entrySize) {
+            success = false;
+            strError = "Truncated header entry at index " + std::to_string(i);
+            break;
+        }
+
+        SHA256_Update(&sha256, &entrySize, sizeof(entrySize));
+        SHA256_Update(&sha256, buf.data(), entrySize);
+
+        // Parse: block_hash + CDiskBlockIndex
+        CDataStream ssEntry(buf.data(), buf.data() + buf.size(), SER_DISK, CLIENT_VERSION);
+        uint256 entryHash;
+        CDiskBlockIndex diskindex;
+        ssEntry >> entryHash;
+        ssEntry >> diskindex;
+
+        // Write to LevelDB as "blockindex" key
+        CDataStream ssKey(SER_DISK, CLIENT_VERSION);
+        ssKey << std::make_pair(std::string("blockindex"), entryHash);
+
+        CDataStream ssValue(SER_DISK, CLIENT_VERSION);
+        ssValue << diskindex;
+
+        batch.Put(ssKey.str(), ssValue.str());
+        nBatchSize++;
+
+        if (nBatchSize >= 1000) {
+            if (!flushBatch()) { success = false; break; }
+        }
+    }
+
+    if (success && !flushBatch())
+        success = false;
+
+    // Read and write UTXOs
+    if (success) {
+        printf("UtxoSnapshot: loading %d UTXOs...\n", numUtxos);
+
+        for (unsigned int i = 0; i < numUtxos; i++) {
+            unsigned int recordSize;
+            if (fread(&recordSize, sizeof(recordSize), 1, file) != 1 || recordSize > 100000) {
+                success = false;
+                strError = "Invalid UTXO record size at index " + std::to_string(i);
+                break;
+            }
+
+            std::vector<char> buf(recordSize);
+            if (fread(buf.data(), 1, recordSize, file) != recordSize) {
+                success = false;
+                strError = "Truncated UTXO record at index " + std::to_string(i);
+                break;
+            }
+
+            SHA256_Update(&sha256, &recordSize, sizeof(recordSize));
+            SHA256_Update(&sha256, buf.data(), recordSize);
+
+            // Parse: txid + output_index + CUtxoEntry
+            CDataStream ssRecord(buf.data(), buf.data() + buf.size(), SER_DISK, CLIENT_VERSION);
+            uint256 txhash;
+            unsigned int nIndex;
+            CUtxoEntry entry;
+            ssRecord >> txhash;
+            ssRecord >> nIndex;
+            ssRecord >> entry;
+
+            // Write to LevelDB with "u" prefix key
+            CDataStream ssKey(SER_DISK, CLIENT_VERSION);
+            ssKey << std::make_pair(std::string("u"), std::make_pair(txhash, nIndex));
+
+            CDataStream ssValue(SER_DISK, CLIENT_VERSION);
+            ssValue << entry;
+
+            batch.Put(ssKey.str(), ssValue.str());
+            nBatchSize++;
+
+            if (nBatchSize >= 50000) {
+                if (!flushBatch()) { success = false; break; }
+
+                if (i % 50000 == 0) {
+                    std::string strMsg = strprintf(_("Loading UTXO snapshot (%d%%)..."),
+                                                   i * 100 / numUtxos);
+                    uiInterface.InitMessage(strMsg);
+                    printf("UtxoSnapshot: loaded %d / %d UTXOs\n", i, numUtxos);
+                }
+            }
+        }
+
+        if (success && !flushBatch())
+            success = false;
+    }
+
+    // Verify content hash
+    if (success) {
+        uint256 actualHash;
+        SHA256_Final((unsigned char*)&actualHash, &sha256);
+
+        if (actualHash != expectedContentHash) {
+            success = false;
+            strError = "Content hash mismatch - snapshot may be corrupted";
+        }
+    }
+
+    // Write metadata
+    if (success) {
+        leveldb::WriteBatch metaBatch;
+
+        // hashBestChain
+        CDataStream ssKey1(SER_DISK, CLIENT_VERSION);
+        ssKey1 << std::string("hashBestChain");
+        CDataStream ssVal1(SER_DISK, CLIENT_VERSION);
+        ssVal1 << blockHash;
+        metaBatch.Put(ssKey1.str(), ssVal1.str());
+
+        // dbformat = 3
+        CDataStream ssKey2(SER_DISK, CLIENT_VERSION);
+        ssKey2 << std::string("dbformat");
+        CDataStream ssVal2(SER_DISK, CLIENT_VERSION);
+        ssVal2 << (int)3;
+        metaBatch.Put(ssKey2.str(), ssVal2.str());
+
+        // version
+        CDataStream ssKey3(SER_DISK, CLIENT_VERSION);
+        ssKey3 << std::string("version");
+        CDataStream ssVal3(SER_DISK, CLIENT_VERSION);
+        ssVal3 << DATABASE_VERSION;
+        metaBatch.Put(ssKey3.str(), ssVal3.str());
+
+        leveldb::Status s = pdb->Write(leveldb::WriteOptions(), &metaBatch);
+        if (!s.ok()) {
+            success = false;
+            strError = "Failed to write metadata: " + s.ToString();
+        }
+    }
+
+    // Clean up LevelDB
+    delete pdb;
+    delete options.filter_policy;
+    delete options.block_cache;
+
+    fclose(file);
+
+    if (!success) {
+        // Remove corrupted/incomplete database
+        printf("UtxoSnapshot: load failed: %s\n", strError.c_str());
+        if (fs::exists(txleveldbPath))
+            fs::remove_all(txleveldbPath);
+        return false;
+    }
+
+    printf("UtxoSnapshot: successfully loaded %d headers + %d UTXOs at height %d\n",
+           numHeaders, numUtxos, height);
+
+    return true;
+}
+
+} // namespace UtxoSnapshot

src/utxosnapshot.h

@@ -0,0 +1,39 @@
+// Copyright (c) 2024-2025 Triangles developers
+// Distributed under the MIT/X11 software license
+
+#ifndef TRIANGLES_UTXOSNAPSHOT_H
+#define TRIANGLES_UTXOSNAPSHOT_H
+
+#include <string>
+#include <boost/filesystem.hpp>
+
+// UTXO snapshot file magic bytes
+static const unsigned int UTXO_SNAPSHOT_MAGIC = 0x53585455; // "UTXS" little-endian
+
+// UTXO snapshot format version
+static const unsigned int UTXO_SNAPSHOT_VERSION = 1;
+
+// Number of block index entries to include in snapshot (covers difficulty,
+// median time, stake modifier, and reorg depth requirements)
+static const unsigned int UTXO_SNAPSHOT_DEFAULT_HEADERS = 2000;
+
+namespace UtxoSnapshot {
+
+    // Create a UTXO snapshot from the current chain state.
+    // Writes last nHeaders block index entries + all UTXOs to destPath.
+    // Returns true on success, sets strError on failure.
+    bool DumpSnapshot(const boost::filesystem::path& destPath,
+                      unsigned int nHeaders,
+                      std::string& strError);
+
+    // Load a UTXO snapshot from a file into a fresh LevelDB.
+    // Writes block index entries, UTXOs, hashBestChain, and dbformat.
+    // The LevelDB must NOT be open yet (call before LoadBlockIndex).
+    // Returns true on success, sets strError on failure.
+    bool LoadSnapshot(const boost::filesystem::path& snapshotPath,
+                      const boost::filesystem::path& dataDir,
+                      std::string& strError);
+
+} // namespace UtxoSnapshot
+
+#endif // TRIANGLES_UTXOSNAPSHOT_H